https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109839
Bug ID: 109839
Summary: -Wanalyzer-fd-leak false positive with routine dup2
Product: gcc
Version: 13.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: eggert at cs dot ucla.edu
Target Milestone: ---
Created attachment 55072
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55072&action=edit
test program illustrating false positive with -Wanalyzer-fd-leak
I ran into this problem when compiling GNU Emacs with GCC 13.1.1 20230426 (Red
Hat 13.1.1-1) on x86-64. Compile the attached program (which is a stripped-down
version) with:
gcc -fanalyzer dup2-analyzer.c
The output is as follows. This is a false alarm, as the dup2 is a routine I/O
redirection and should not be considered to be a leak. In typical use, it's
better to not consider dup2's return value to be a leak.
dup2-analyzer.c: In function ‘main’:
dup2-analyzer.c:6:6: warning: leak of file descriptor ‘dup2(1, 2)’ [CWE-775]
[-Wanalyzer-fd-leak]
6 | if (dup2 (STDOUT_FILENO, STDERR_FILENO) < 0)
| ^
‘main’: events 1-2
|
| 6 | if (dup2 (STDOUT_FILENO, STDERR_FILENO) < 0)
| | ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | ||
| | |(1) opened here
| | (2) ‘dup2(1, 2)’ leaks here; was opened at (1)
|
